1. Field of the Invention
The present invention relates to an optical semiconductor device and an optical semiconductor module equipped with it, and more particularly to those with a low-profiled structure of the optical semiconductor device which light is incident to or exits from. The present invention intends to realize the compacting or low-profiling of the components using them.
2. Description of the Related Art
In recent years, multi-media components such as a "sub-note personal computer", a portable information terminal, electronic still camera, etc. are developing rapidly.
In addition, seven million portable components are sold in a year, and about 80% of them adopt an infrared rays system in IrDA (Infrared Data Association) standard. This system requires transmission/reception between an external device and a main body using an infrared ray signal. Therefore, a light emitting element for emitting infrared rays and a light receiving element for receiving them are required.
Further, the optical head used in an optical recording/playing device such as an "MD" or "CD" makes recording/reproducing information by irradiating an optical recording medium with a beam and detecting the modulated beam therefrom. In this case, the light emitting element and light receiving element are required.
However, these light emitting elements and light receiving elements have not been miniaturized sufficiently. FIG. 15 shows an example of a semiconductor device equipped with an optical device which is disclosed in Japanese Patent Publication. 7-28085. In FIG. 15, a semiconductor laser 1 is directly placed on a semiconductor substrate 2, and a prism 3 having a trapezoidal sectional shape is secured on the semiconductor substrate 2. Reference numeral 4 denotes an optical recording medium.
A slope 5 of the prism 3 opposite to the semiconductor laser 1 is a semi-transparent reflecting face. A prism face 6 in contact with the semiconductor substrate 2 constitutes a reflecting face at the other portion than a photodetector (light-receiving element) 7. A prism face 8 opposite to the face 6 also constitutes a reflecting face.
A beam 9, which is emitted from the semiconductor laser 1 and is incident on the prism 3 from the slope 5, is reflected from the reflecting faces 6 and 8, and detected by a photodetector 7.
On the other hand, FIG. 16 shows an infrared ray data communication module 11 incorporating an infrared ray LED, LED driver, PIN photodiode and an amplifier, etc. In this module, light emitted from the LED 12 mounted on a substrate is caused to exit through a lens 13. The light is incident on a photodiode 14 mounted on the substrate through a lens 15.
The module as shown in FIG. 15, in which the optical component is mounted above the semiconductor substrate, requires a very sophisticated technique and is high in production cost.
In the module as shown in FIG. 16, emission or reception of light must be made on a mold body and another semiconductor device must be set at an opposite position. Therefore, the entire resultant system is increased in thickness and cannot be miniaturized.
If the emission or reception of light in a horizontal direction is intended in the module in FIG. 16, a lead 16 to the optical semiconductor device 11 must be bent at 90.degree.. The manner of bending the lead 11 influences the stability of securing the semiconductor device 11.